Problem in torontonian sampling algo

PennyLane Help
1

Hey! I am trying torontonian_sample_graph() and had set the cutoff to 9 but unfortunately, I only get 1 or 0 photons per output mode**

G=gnp_random_graph(12,0.6)

A= adjacency_matrix(G).todense()

P=torontonian_sample_graph(A,35,cutoff=9)

P

2

Hi @MUSHKAN_SUREKA,

I can confirm that I also get that ‘P’ only contains ones and zeros. I’m consulting with a colleague about this. I will post a message here as soon as we have an answer.

Thank you for your question!

3

Hi @MUSHKAN_SUREKA,

I’m back with an answer! My colleague Sebastián helped me figure out the details.

The torontonian corresponds to the problem of Gaussian Boson Sampling with threshold detectors: these measure 0 if there’s no detection and 1 if there’s detection of something.

So the 0’s and 1’s don’t represent the number of photons per mode, they simply state whether or not something was detected.

Knowing this I would guess that you probably want to calculate the hafnian instead of the torontonian.

I hope this is helpful!